package Solutions

func findTheDifference(s string, t string) byte {
    mp:=make(map[byte]int,len(s))
    for i:=0;i<len(s);i++{
        mp[s[i]]++
    }
    for i:=0;i<len(t);i++{
        if v,ok:=mp[t[i]];!ok{
            return t[i]
        }else{
            if v==0{
                return t[i]
            }
            mp[t[i]]--
        }
    }
    return 0
}